Conveyor trolley with camming heads

ABSTRACT

An improved conveyor trolley system of the type in which a series of load-carrying trolleys are supported in rolling suspension from an overhead monorail track, and are moved by pushing engagement between successive trolleys. The invention resides in the combination of a track with predetermined curvature range, trolleys of predetermined maximum length, and leading and trailing camming means on each trolley to insure smooth pushing engagement when a trolley series of the specific type is moved on a track of the specified type. One preferred species includes a skirt cam for inhibiting derailment of the trolley when traveling on a track of the specified type. Another preferred species provides the cam surfaces in a unitary formed sheet metal body incorporated in each trolley head assembly.

United States Patent 91 Paglia 1 CONVEYOR TROLLEY WITH CAMMING HEADS[76] Inventor: Marius F. Paglia, 2913 Westbrook Ave., Hollywood, Calif.90046 [22] Filed: Nov. 27, 1972 [21] Appl. No.: 309,672

[52] US. Cl. 104/93, 105/150 [51] Int. Cl EOlb 25/22 [58] Field ofSearch 105/148, 150, 152, 156;

[56] References Cited UNITED STATES PATENTS 2/1953 Finkbeiner 105/1506/1971 Weiss 105/152 l/l972 Kavieff 104/172 8.]

Primary Examiner-M. Henson Woods, Jr. Assistant Examiner-D. W. KeenAttorney, Agent, or Firm-Edmond F Shanahan Aug. 6, 1974 5 7 ABSTRACT Animproved conveyor trolley system of the type in which a series ofload-carrying trolleys are supported in rolling suspension from anoverhead monorail track, and are moved by pushing engagement betweensuccessive trolleys. The invention resides in the combination of a trackwith predetermined curvature range, trolleys of predetermined maximumlength, and leading and trailing camming means on each trolley to insuresmooth pushing engagement when a trolley series of the specific type ismoved on a track of the specified type.

One preferred species includes a skirt cam for inhibiting derailment ofthe trolley when traveling on a I track of the specified type.

Another preferred species provides the cam surfaces in a unitary formedsheet metal body incorporated in each trolley head assembly.

6 Claims, 8 Drawing Figures CONVEYOR TROLLEY WITH CAMMING HEADSSPECIFICATION This invention relates generally to conveyor trolleys ofthe type in which a series of load-carrying trolleys, hanging in rollingsuspension from an overhead monorail track, are moved by end-to-endpushing engage ment, and/or power projection. Such trolleys are used inmany factory and warehouse applications, but they have achievedparticularly widespread use in garment warehouses because of theircleanliness, lack of fire hazard, and general usefulness in carryinglight and medium loads.

Moreover, such trolleys have been successfully adapted to an economicsystem of automation particularly suited for garment handling. In theautomation system, the track has main and branch lines. Switching meanscapable of automatic or manual actuation are located at turn-off pointsfor each branch. Trolleys may also be provided with switch actuatingmeans which may be selectively set to divert that trolley into any oneof many predetermined branch tracks. The person operating the conveyortrolley system may load an individual trolley with a specifiedassortment of garments which it is desired to divert to a designatedbranch; he may then set the switch actuating means on that trolley sothat it will be automatically diverted from the main track to thedestination branch track, as it is pushed along by means of power, in aseries of individual trolleys.

In a typical installation of a conveyor trolley system of the typedescribed, the warehouses are huge, and are operated by a relativelysmall crew of operating personnel, who are stationed at various worklocations. The utility and economy of such an installation is lost ifthe conveyor line is frequently brought to a standstill by jamming atsome point in the track remote from an operator's station.

Unfortunately, the utility and economy of such conveyor installationshas been much impaired by tendencies of the trolleys to be derailed bythe pushing force, particularly when a long series of trolleys must bepushed along a track with many curves and inclines. The problems oftrolley derailmenthave arisen with new difficulties in each newinstallation. Generally, each new installation has required trackconfirgurations not found in prior installations, so that experiencecould not be relied upon to assure satisfactory operation of a newlydesigned conveyor trolley system. On the contrary, movers have had toresign themselves to building the system and then debugging it after itsparticular jamming problems were developed during initial operation.

It is the primary object of this invention to provide a novelcombination of track and trolley with much greater resistance toderailment, than in previously known pusher type conveyor trolleysystems, and moreover to achieve the superior features described hereinafter by means of a construction lower in cost than previously knownconveyor trolley systems.

A second object is to provide an improved trolley system in whichderailment and jamming tends to be selfcorrecting, without personalattendance of the operator.

Still another object is to provide a conveyor trolley system whoseability to perform without jamming is much more predictable, when thepresent invention is employed, than has been in the case of conveyorsystems heretofore employed.

The foregoing and other objectives of the invention are achieved byincorporating into each individual trolley a complementary cam structureat the leading and trailing ends, to insure smooth pushing engagementbetween successive trolleys, when they are traveling on a track of aspecified co-acting type.

The same structure which incorporates the pushing engagement camstructures may also incorporate a derailment inhibiting cam for engagingthe track at moments of partial derailment, and tending to force thetrolley back onto the track.

The foregoing and other objects and advantages of the invention willbest be understood from the following description of one preferredspecific embodiment, which should be read with reference to theaccompanying drawings.

The drawings illustrate the incorporation of the invention into aconveyor trolley system having many features already in widespread use,and familiar to those having knowledge of the art.

The track is usually steel tubing, typically 1-1/16 inches or l-5/ l 6inches in outside diameter. This tubing is bent into the desired curvesand inclines, along which the individual trolleys are required totravel.

Each trolley is comprised of a load-carrying structure (typically ahorizontal bar for hanging garments) which is suspended from the trackat its leading and trailing ends by means of a trolley head assembly.The longitudinal dimension of an individual trolley is oftensufficiently great in relationship to the curvature of the track to bean important cause of the operating difficulties already mentioned.

It will be understood that successive individual trolleys are notconnected to one another; a series of trolleys is merely pushed alongthe track by end-to-end engagement. However, although there is nopositive coupling employed, the present invention uses a nesting camsystem at the leading and trailing ends of each trolley, so that many ofthe advantages of a coupling are accomplished without actually employinga positive connection. It will, therefore, be convenient to describe thenesting leading and trailing cam surfaces as coupling cam surfaces.

Also, it will be understood that the track incorporates many upward anddownward inclines; not all the track curvature is in a horizontal plane.Nevertheless, for convenience, the term track curvature will be employedto include all departures of a track from a perfectly straight line.

It will be necessary to make several references to the track as anoverhead monorail, or to track rollers as being disposed above" thetrack in a horizontal plane. References will likewise be made tovertical transverse planes, etc. It will be understood that these referto the geometric relationships between track and trolley in the normalstraight-line horizontal track characteristic of the greatest part ofthe typical conveyor installation. Actually, at inclined places, thesegeometric definitions do not apply.

Also, because of the substantial length of a typical individual trolley,as compared with curvature in the track, the longitudinal center line ofa trolley will not be disposed in the same vertical plane as thelongitudinal center line of the track at places of curve and incline.Nevertheless, for purposes of description, it is convenient to refer tothese longitudinal centerlines, and other geometric relationships, withreference to the relationships which exist when the trolley is movingalong a straight-line horizontal section of track substantially longerthan the longitudinal dimension of the trolley. It will be understoodthat departures from this geometry will occur at curves and inclines.

In the drawings:

FIG. 1 is a left side elevational view of a leading trolley headconstructed according to the present invention;

FIG. 2 is a plan view of the head of FIG. 1;

FIG. 3 is a rear elevational view of the head of FIGS. 1 and 2;

FIG. 4 is a right side elevational view of the head of FIGS. 1 to 3;

FIG. 5 is a right side elevational view of a trailing head form of theinvention;

FIG. 6 is a perspective view of a stamped metal body incorporating thecoupling cam features of the invention;

FIG. 7 is a right side elevational view of a series of two trolleys,each suspended by a pair of trolley head assemblies illustrated in FIGS.1 to 5, shown as the second trolley pushes the first up an upwardlyinclined section of conveyor track; and

FIG. 8 is a perspective view of a sharp right turn bend in a section oftrack, showing (fragmentarily) a series of two trolleys as theynegotiate the turn with their ends in pushing engagement.

In the drawings, the general conveyor trolley system is suggested onlyfragmentarily in FIGS. 7 and 8, and indicated by the numeral 10, sincethe present invention is an improvement on a system well known to thoseskilled in the particular art, as to features not illustrated in thedrawing.

The standard tubular track 11 is shown in a typical upward movingincline in FIG. 7 and in a typical right turn in a horizontal plane inFIG. 8.

The manner of suspending the track 11 from the ceiling or some type offrame structure, without interfering with the free passage of thetrolleys is illustrated only fragmentarily because the construction andinstallation of such suspension is well known to those skilled in theart of this conveyor. It will be seen that the track 11 is supported atspaced intervals by C-supports 12, which are adjustably clamped at 13 todownhanging overhead tubular support 14 (see FIG. 8).

A series of trolleys travel along track 11 in end-toend pushingengagement as illustrated in FIGS. 7 and 8, in which two individualtrolleys are identified by the numerals 15 and 16.

The direction of movement of the trolleys l5 and 16 is indicated by thearrow 17, and may be conveniently referred to as movement in adownstream or downtrack direction.

Typically, all the trolleys in a given system are identical. However,some installations may permit or require an assortment of trolleys; theinvention will be applicable if its limitations are met. Also, thetrolley designs are as diverse as their many applications. In thepresent embodiment, a typical garment trolley is illustrated.

Trolley 15 is seen to be comprised of a garmentcarrying bar 18, and apair of trolley head assemblies, a leading trolley head assembly 19, anda trailing trolley head assembly 20. Garment-carrying bar 18 is providedwith a number of upward projecting stops 21 to prevent the sliding ofgarment hangers when trolley 15 is traveling on an inclined part oftrack 11.

The most readily observable structural features of the invention are inthe trolley head assemblies 19 and 20, which are illustrated in FIGS. 1to 4, although, as will be explained hereinafter, there is a cooperatingrelationship between cam surfaces incorporated in the trolley headassembly, and the structure of both track 11 and trolley 15.

Leading trolley head assembly 19 is illustrated in detail in FIGS. 1 to4. Typically, the trailing trolley head assembly 20, illustrated in FIG.5, is identical in all respects to leading trolley head assembly 19,except for certain differences related to a species of the invention inwhich automatic switching is employed, as will be explained hereinafter.

In FIG. 3, the viewer sees leading trolley head assembly 19 as it movestoward the viewer on tubular track 11 (seen in transversecross-section). Referring to FIG. 3, and to the plan view of FIG. 2, andthe left and right side views of FIGS. 1 and 4 respectively, one seesthat the parts of assembly 19 are assembled on a vertically extendedhanger 30. At its lower end, hanger 30 carries a hanger swivel 31 forproviding swiveling attachment to the leading end of carrier bar 18. Inthe preferred embodiment illustrated, hanger 30 is in the form of a boxformed out of sheet steel, with an open face at the right side, outboardof track 11, for accommodating selectively positionable automatic switchactuators 35 seen in FIG. 4.

The swivel 31 is preferably a vertically disposed swivel shaft 36,mounted in a swivel shaft support 37, which projects under track 11 soas to dispose the vertical axis 38 of swivel shaft 36 in a verticalplane lying in the longitudinal axis of (a straight-line portion oftrack 11. Typically, swivel shaft 36 rotatably swivels in the leadingend 18a of carrier bar 18.

The upper end of hanger 30 carries a body shaft 40, which projectshorizontally, transversely to track 11, over track 11.

Shaft 40 provides swiveling attachment of a body 41, which may bereferred to as roller body 41, since it carries a pair of rollers 42 and43 which roll on tubular track 11 as best seen in the head-on view ofFIG. 3. Preferably rollers 42 and 43 are symmetrically recessed to rideon the cylindrical surface of tubular track 11. Rollers 42 and 43 arerotatable on shafts 44 and 45, which are mounted in body 41.

It will be seen that the axis of body swivel shaft 40 is horizontal, andtransverse to tubular track 11, and spaced above a horizontal planedefined by the axes of roller shafts 44 and 45.

It will also be seen from FIGS. 1 to 4 that the swiveling action of body41 around body shaft 40 is limited by a body-swiveling stop 47, whichprojects inwardly toward tubular track 11, from the left side of hanger30, and limits the rotation of body 41 about shaft 40.

Body 41 is illustrated in perspective in FIG. 6, and entirelydisassembled from leading trolley head assembly 19. Body 41 is shown inthe preferred form of the invention as formed entirely as a unit out ofstamped sheet metal. This construction is not only betterfor purposes ofthe invention, but also less expensive, than fabrication by casting asgenerally employed in the prior art, and heretofore believed to be thepreferred method of fabrication. Stamped sheet metal has uniqueadvantages in providing the smooth camming surfaces required by thepresent invention, as will be seen hereinafter.

FIG. 6 reveals that body 41 has what may be referred to as an invertedchannel construction with an inboard skirt 51 (adjacent hanger 30 in theassembly 19) and an outboard skirt 52. Also, body 41 has its sheetmate-. rial downfolded at leading and trailing ends to form a smoothlycontoured projecting leading cam 53 and a smoothly contoured recessedtrailing cam 54. Preferably, projecting leading cam 53 and recessedtrailing cam 54 are symmetrical about a central plane passing throughthe center line of body 41, and containing the longitudinal axes of bothtubular track 11 and carrier bar 18, as well as the vertical axes 38 ofhanger swivel shaft 36. Also preverably, the outboard skirt 52incorporates a skirt cam indicated generally by the number 55, andincluding a central portion 56 closely approaching track 11, andoutwardly diverging leading and trailing portions 57 and 58,respectively. Preferably, skirt cam 55 is symmetrical about a verticalplane transverse to track 11, and passing through both axes 38 and theaxes of body shaft 40.

Trailing trolley head assembly 20, seen in FIG. 5, and also in FIGS. 7and 8, is substantially the same assembly as used for leading trolleyhead assembly 19; indeed, an identical assembly may be employed.However, in the preferred form illustrated, trailing cam 20 does notcarry any switch actuating means 35, and consequently the trailingassembly 20 employs a much smaller hanger 60.

It is important to understand that there is a co-acting relationshipbetween track 11, the maximum trolley links (i.e., spacing along thetrack between trolley heads of the same trolley), and the configurationof the cam surfaces employed in body 41. For the successful functioningof the inventive combination, these three are related to produce anoptimum combination of design flexibility and operating reliability. Allcurves in track 11 should fall within a range of permitted curvature(including horizontal curves, inclines, or combinations of both). Themaximum permitted length of an individual trolley 15 or 16 shouldcorrespond to the permitted track curvature range so as to restrictturning angles between two successive trolleys to a suitablepredetermined range. The two foregoing ranges will in turn determine, orbe determined by, the cam surfaces employed on body 41. The leading andtrailing coupling cam surfaces 53 and 54 must provide the best pushingengagement consistent with turning curves within the permitted trackcurvature range as illustrated in FIG. 8. Also, the skirt cam 55 mustprovide a configuration of the diverging portions 57 and 56 whichaccommodates the curvature of track 11, without producing jamminginterference between skirt 55 and track 11. Leading cam 53 and trailingcam 54 must have suitable camming characteristics in the vertical planeso that override jamming does not occur at an incline, such as pushingup an incline illustrated in FIG. 7, provided the curvature incline oftrack 11 is kept within the permitted range predetermined by thecombination.

The pushing earns 53 and 54, and the skirt cam 55 provide a muchimproved and more reliable form of trolley for automatic switching. Inthe automatic switching procedure described in preceding paragraphs, itis important that one and only one trolley be diverted by a singleautomatic switch operation and that no jamming occur at the junction ofthe branch track to the main track. The cams of body 41 of the presentinvention provide smooth and powerful pushing engagements throughoutmost of the branch turnoff, so taht switching errors are less likely tooccur, and also so that slightly imperfect operation of the switchesdoes not produce jamming at the branch track junction.

In many installations, the narrow hanger 60 is sufficient for use in aleading trolley head assembly, as well as the trailing head assembly. Insuch installations, both leading and trailing trolley head assemblieswould look exactly like trailing trolley head assembly 20 in FIG. 5. Itis more convenient to have only one type of hanger, hanger 60,throughout the entire system, unless the automatic switch actuation isof sufficient complexity to require the use of the larger trolley headassembly illustrated in FIGS. 1 to 4.

The preferred embodiment of the invention has been described with thetrolleys traveling in the direction indicated by the arrow 17 in FIG. 8,that is, with the projections 53 leading and the recessed 54 trailing.However, in some installations, because of the location of C-supports12, on the opposite side of track 11 from that indicated in FIG. 8, itis necessary to have the trolleys traveling oppositely to the directionindicated by arrow 17, to wit: with recesses 54 leading and projects 53trailing. Even in this form of operation, the invention is found toaccomplish substantial coupling between successive trolleys, andderailment is much inhibited by the camming action between trailingprojections 53 and leading recesses 54.

I claim:

1. In a conveyor trolley system in which a series of load-carryingtrolleys are movable in rolling suspension from an overhead monorailtrack, an improved system which includes:

a series of trolleys, each of which has a longitudinal dimensiontalong alongitudinal axis substantially parallel to straight line portions ofsaid track, said longitudinal dimension being limited to a predeterminedmaximum for any single trolley;

a monorail track including curved portions restricted to a predeterminedrange of curvature related to said maximum longitudinal dimension for asingle trolley to limit the range of turning angle between longitudinalaxes of two successive trolleys in pushing engagement with each other;and

each of said trolleys in said series of trolleys including;

a carrier member extending along the longitudinal axis of said trolley;

a pair of trolley head assemblies carrying said carrier member inrolling suspension from said track, said pair comprising a leading headand a trailing head at the leading and trailing ends, respectively, ofsaid carrier, each of said head assemblies including:

a series of two rollers rolling on the upper surface of said track, saidrollers having bearing axes transverse to said track, said roller axesdefining a horizontal roller axis plane spaced above said track;

a body in which said two roller members are rotatably mounted, said bodyoverhanging said rollers, said body including coupling cam surfaces formaking smooth pushing engagement between successive trolleys on saidtrack;

a hanger disposed to one side of said track and extending verticallyfrom said carrier to an elevation above said roller axis plane;

a vertical hanger swivel for connecting the lower end of said hanger tosaid carrier and permitting said hanger to swivel about a verticalhanger axis;

a horizontal body swivel for connecting the upper end of said hanger tosaid body at an elevation above said roller axis plane and permittingsaid body to swivel with respect to said hanger about a horizontal bodyaxis transverse to said track and midway between said roller axes; and

a skirt cam integral with said body and extending downwardly adjacentthe side of said track opposite the side at which said hanger isdisposed, said skirt cam having a wall surface adjacent said track,which wall surface smoothly diverges downwardly away from the side ofsaid track in both leading and trailing directions to inhibit derailmentof said trolley head assembly while permitting accommodation of saidassembly to said predetermined track curvature.

2. An improved conveyor trolley system as described in claim 1, in whicheach of said bodies is a single piece of formed metal sheet comprisingan inverted channel section disposed longitudinally with respect to saidtrack, and providing, in its downwardly extending walls, bearinglocations for the mounting of said rollers and said body swivel; adownwardly extending side extension formed to provide said skirt cam;and folded sheet material at leading and trailing ends formed to providesaid coupling cam surfaces.

3. An improved conveyor trolley system as described in claim 2, in whichsaid formed sheet metal body has sheet material downfolded at theleading end formed into a projecting cam surface having a maximumprojection at a vertical plane corresponding to the longitudinal centerline of said track; and sheet material at the trailing end of said bodyis downfolded to form a recessed cam, with maximum recess depth at saidvertical plane.

4. An improved conveyor trolley system as described in claim 1, inwhich, in said trolley head assemblies, said hanger carries a stop meanslocated on said hanger adjacent said body, for limiting the rotation ofsaid body about said horizontal body axis to a predetermined bodyswiveling angle related to the predetermined range of vertical curvaturewhich can be negotiated by said leading and trailing coupling camsurfaces.

5. An improved conveyor trolley system as described in claim 1, in whichsaid skirt cam is formed with a central portion having minimum clearanceof said track, in straight line parts of said track, said centralportion being disposed in a vertical plane through said hanger swivelaxis, and said skirt cam diverging outwardly from said track, andstraight line portions of said track, in both leading and trailingdirections, to permit a predetermined range of track curvature withoutengagement between said skirt cam and said track, except when said skirtcam is operating to inhibit derailment of the trolley head assembly fromsaid track.

6. An improved conveyor trolley system as described in claim 1, in whichsaid coupling cam surfaces are comprised in a projection at the leadingend of each of said bodies, having a line of maximum projection in avertical plane corresponding to the center line of said track; arecessed surface in the trailing end of said body, having a line ofmaximum recess in said vertical plane; and said vertical axis of saidhanger swivel is disposed in said vertical plane.

1. In a conveyor trolley system in which a series of loadcarryingtrolleys are movable in rolling suspension frOm an overhead monorailtrack, an improved system which includes: a series of trolleys, each ofwhich has a longitudinal dimension along a longitudinal axissubstantially parallel to straight line portions of said track, saidlongitudinal dimension being limited to a predetermined maximum for anysingle trolley; a monorail track including curved portions restricted toa predetermined range of curvature related to said maximum longitudinaldimension for a single trolley to limit the range of turning anglebetween longitudinal axes of two successive trolleys in pushingengagement with each other; and each of said trolleys in said series oftrolleys including; a carrier member extending along the longitudinalaxis of said trolley; a pair of trolley head assemblies carrying saidcarrier member in rolling suspension from said track, said paircomprising a leading head and a trailing head at the leading andtrailing ends, respectively, of said carrier, each of said headassemblies including: a series of two rollers rolling on the uppersurface of said track, said rollers having bearing axes transverse tosaid track, said roller axes defining a horizontal roller axis planespaced above said track; a body in which said two roller members arerotatably mounted, said body overhanging said rollers, said bodyincluding coupling cam surfaces for making smooth pushing engagementbetween successive trolleys on said track; a hanger disposed to one sideof said track and extending vertically from said carrier to an elevationabove said roller axis plane; a vertical hanger swivel for connectingthe lower end of said hanger to said carrier and permitting said hangerto swivel about a vertical hanger axis; a horizontal body swivel forconnecting the upper end of said hanger to said body at an elevationabove said roller axis plane and permitting said body to swivel withrespect to said hanger about a horizontal body axis transverse to saidtrack and midway between said roller axes; and a skirt cam integral withsaid body and extending downwardly adjacent the side of said trackopposite the side at which said hanger is disposed, said skirt camhaving a wall surface adjacent said track, which wall surface smoothlydiverges downwardly away from the side of said track in both leading andtrailing directions to inhibit derailment of said trolley head assemblywhile permitting accommodation of said assembly to said predeterminedtrack curvature.
 2. An improved conveyor trolley system as described inclaim 1, in which each of said bodies is a single piece of formed metalsheet comprising an inverted channel section disposed longitudinallywith respect to said track, and providing, in its downwardly extendingwalls, bearing locations for the mounting of said rollers and said bodyswivel; a downwardly extending side extension formed to provide saidskirt cam; and folded sheet material at leading and trailing ends formedto provide said coupling cam surfaces.
 3. An improved conveyor trolleysystem as described in claim 2, in which said formed sheet metal bodyhas sheet material downfolded at the leading end formed into aprojecting cam surface having a maximum projection at a vertical planecorresponding to the longitudinal center line of said track; and sheetmaterial at the trailing end of said body is downfolded to form arecessed cam, with maximum recess depth at said vertical plane.
 4. Animproved conveyor trolley system as described in claim 1, in which, insaid trolley head assemblies, said hanger carries a stop means locatedon said hanger adjacent said body, for limiting the rotation of saidbody about said horizontal body axis to a predetermined body swivelingangle related to the predetermined range of vertical curvature which canbe negotiated by said leading and trailing coupling cam surfaces.
 5. Animproved conveyor trolley system as described in claim 1, in which saidskirt cam is formed with a central portion having minimum clearance ofsaid track, in straight line parts of said track, said central portionbeing disposed in a vertical plane through said hanger swivel axis, andsaid skirt cam diverging outwardly from said track, and straight lineportions of said track, in both leading and trailing directions, topermit a predetermined range of track curvature without engagementbetween said skirt cam and said track, except when said skirt cam isoperating to inhibit derailment of the trolley head assembly from saidtrack.
 6. An improved conveyor trolley system as described in claim 1,in which said coupling cam surfaces are comprised in a projection at theleading end of each of said bodies, having a line of maximum projectionin a vertical plane corresponding to the center line of said track; arecessed surface in the trailing end of said body, having a line ofmaximum recess in said vertical plane; and said vertical axis of saidhanger swivel is disposed in said vertical plane.